Compare-mode bundle treemap diff to spot per-route size regressions

Frontend teams running micro-frontends, monorepos, and aggressive code-splitting routinely lose visibility into which routes or pages drive bundle size regressions, because most CI checks report only total bundle size and not per-route deltas. This problem hits product and platform engineers at mid-market and enterprise web teams—roughly 2,000,000 potential buyers within a $6.0B developer tooling market—where regressions of tens to hundreds of kilobytes can meaningfully degrade user experience and conversion. You could build a compare-mode treemap diff that ingests build artifacts and source maps from common bundlers (Webpack, Vite, esbuild), maps chunks to routes and components, and surfaces per-route size deltas with provenance, line-level attribution, and automated PR comments. Pair that with CI gating, a focused UI that ranks the top N regressions by absolute kB and percentage, and SDKs for monorepos and micro-frontend topologies to minimize integration friction. Timing is favorable: shift-left observability is growing, deployment platforms expect build-time insights, and an average willingness-to-pay around $3,000 ACV for mid-market/enterprise dev tooling makes the $6.0B opportunity realistic. To stand out from medium-competition alternatives, prioritize high-fidelity route attribution (not just bundle-level diffs), reduce false positives with robust source-map-aware attribution, and ship turnkey CI and platform integrations for fast adoption. The main challenges are handling diverse build outputs, SSR and dynamic import mapping, and proving clear ROI to engineering managers, but solving those will create a defensible product that teams will adopt and pay for.